tests/zfs-tests/tests/functional/procfs/procfs_list_stale_read.ksh

   1 #!/bin/ksh -p
   2 #
   3 # CDDL HEADER START
   4 #
   5 # The contents of this file are subject to the terms of the
   6 # Common Development and Distribution License (the "License").
   7 # You may not use this file except in compliance with the License.
   8 #
   9 # You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10 # or http://www.opensolaris.org/os/licensing.
  11 # See the License for the specific language governing permissions
  12 # and limitations under the License.
  13 #
  14 # When distributing Covered Code, include this CDDL HEADER in each
  15 # file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16 # If applicable, add the following below this CDDL HEADER, with the
  17 # fields enclosed by brackets "[]" replaced with your own identifying
  18 # information: Portions Copyright [yyyy] [name of copyright owner]
  19 #
  20 # CDDL HEADER END
  21 #
  22
  23 #
  24 # Copyright (c) 2018 by Delphix. All rights reserved.
  25 #
  26
  27 . $STF_SUITE/include/libtest.shlib
  28
  29 #
  30 # DESCRIPTION:
  31 # Make sure errors caused by messages being dropped from the list backing the
  32 # procfs file are handled gracefully.
  33 #
  34 # STRATEGY:
  35 # 1. Make sure a few entries have been logged.
  36 # 2. Open the procfs file and start reading from it.
  37 # 3. Write to the file to cause its contents to be dropped.
  38 # 4. Resume reading from the first instance, and check that the expected
  39 #    error is received.
  40 # 5. Repeat steps 1-4, except instead of dropping all the messages by writing
  41 #    to the file, cause enough new messages to be written that the old messages
  42 #    are dropped.
  43 #
  44
  45 function cleanup
  46 {
  47         echo $default_max_entries >$MAX_ENTRIES_PARAM || log_fail
  48 }
  49
  50 function sync_n
  51 {
  52         for i in {1..$1}; do
  53                 log_must zpool sync $TESTPOOL
  54         done
  55         return 0
  56 }
  57
  58 function do_test
  59 {
  60         typeset cmd=$1
  61
  62         # Clear out old entries
  63         echo 0 >$TXG_HIST || log_fail
  64
  65         # Add some new entries
  66         sync_n 20
  67
  68         # Confirm that there actually is something in the file.
  69         [[ $(wc -l <$TXG_HIST) -ge 20 ]] || log_fail "expected more entries"
  70
  71         #
  72         # Start reading file, pause and run a command that will cause the
  73         # current offset into the file to become invalid, and then try to
  74         # finish reading.
  75         #
  76         {
  77                 log_must dd bs=512 count=4 >/dev/null
  78                 log_must eval "$cmd"
  79                 cat 2>&1 >/dev/null | log_must grep "Input/output error"
  80         } <$TXG_HIST
  81 }
  82
  83 typeset -r TXG_HIST=/proc/spl/kstat/zfs/$TESTPOOL/txgs
  84 typeset MAX_ENTRIES_PARAM=/sys/module/zfs/parameters/zfs_txg_history
  85 typeset default_max_entries
  86
  87 log_onexit cleanup
  88
  89 default_max_entries=$(cat $MAX_ENTRIES_PARAM) || log_fail
  90 echo 50 >$MAX_ENTRIES_PARAM || log_fail
  91
  92 # Clear all of the existing entries.
  93 do_test "echo 0 >$TXG_HIST"
  94
  95 # Add enough new entries to the list that all of the old ones are dropped.
  96 do_test "sync_n 60"
  97
  98 log_pass "Attempting to read dropped message returns expected error"